
%\documentclass[letterpaper,12pt]{article}
%\usepackage[x11names,rgb]{xcolor}
%\usepackage{tikz}
%\usetikzlibrary{snakes}
%\usetikzlibrary{arrows}
%\usetikzlibrary{shapes}
%\usetikzlibrary{backgrounds}
%\usepackage{amsmath}
%\oddsidemargin 0in
%\evensidemargin 0in
%\topmargin 0in
%\headheight 0in
%\headsep 0in
%\textheight 9in
%\textwidth 6.5in
%\begin{document}
%\pagestyle{empty}
%\vspace*{\fill}
%\begin{center}
\documentclass{article}
 
\usepackage[pdftex,active,tightpage]{preview}
\usepackage{tikz}
\usetikzlibrary{snakes}
\usetikzlibrary{arrows}
\makeatletter
 
\begin{document}
\begin{preview}
	%%
	\begin{tikzpicture}[scale=1.0]
	 
	 \fill[semitransparent, black!30] (0,0) rectangle (3,3);
	
	 \fill[opaque, white] (1,1) rectangle (2,2);
	 
	 \draw[thick, xstep=1, ystep=1] (0,0) grid (3,3);
	 
	 %Labels
	 
	 \draw (1.5,1.5) node {\textbf{N}};
	 
	 % Current Octant
	 \draw (1.5,-0.5) node {Neighbours of {\textbf{N}}};
	 \draw (1.5,-1) node {at level $\mathcal{L}(\textbf{N})$};
	 \draw[->] (1.5,-0.25) -- (0.5,0.5);
	 
	\end{tikzpicture}%%
\end{preview}
\end{document}

%\end{center}
%\vspace*{\fill}
%\end{document}

    	